xii Illustrations 



PAGE 



The Rising Waters of Gatun Lake . . 54 



Cattle ON Low Pasture Lands : Panama . 56 



The Effect of Floods : Empire ... 58 



Alg^ United with Oil in Mat-like Masses : 

 Empire 58 



Railroad Tie Left in a Tree by a Subsiding 

 Flood ....... 62 



Oiling of Breeding Places along a River- 

 Bank ....... 64 



Vegetation Protecting Mosquito Larvae . 66 



A Seepage Outcrop, Controlled by an Inter- 

 cepting Tile Ditch : Ancon ... 68 



Vegetation Removed from the Edge of a 

 Pond at Bohio ..... 70 



Result of Blocking the Rio Cardenas . 72 



Propagation Area of Gatun Mosquito 

 Influx where Mosquito Flight was 

 Discovered ...... 76 



Detail of Anopheles Breeding Grouito 

 WHERE Flight Observations were Made 78 



Grass and Plants almost Covering the 

 Water Surface and Protecting Mosquito 

 Larv^ 78 



Diagrams Showing best Locations for 

 Screened Doors 87 



